help in understanding LZ78 compressing method

[johny doe]

i cant understand this method

here is an example
we are tring to compress
abbacabbcbcd

and we get the result
of
(0,a) , (0,b), (2,a) , (0,c) , (1,b) , (2,c) , (6,d)

where the numbers are some sort of indicator for the char or a group
of chars

i cant figure out how they got those numbers
??

and what methods do i need to create in order to
build it??
[ December 29, 2007: Message edited by: johny doe ]

[Nicholas Jordan]

Mastering Algorithms With C - OReilley.
The main idea behind LZ77 is to look continually for the longest phrase in the lookahead buffer that matches a phrase currently in the dictionary.